Method for detecting deterioration defect of structural part

A method for detecting deterioration defect of a structural part, comprising:

• detecting a waveform of time domain of the structural part by a sensor disposed on the structural part;
• performing a conversion of time domain to frequency domain for the waveform of time domain by a processor electrically connected to the sensor so as to obtain an actual modal parameter of each of a plurality of modals related to a waveform of frequency domain of the structural part;
• comparing the actual modal parameter of each of the plurality of modals to modal parameter information stored in a database to determine whether a deterioration defect exists in the structural part;
• and
• determining a degree and a position of the deterioration defect when the deterioration defect exists in the structural part;
• wherein the modal parameter information comprises sets of comparison modal parameters, and each of the sets of comparison modal parameters indicates a respective one of the deterioration defect of the position and other deterioration defects of other positions in the structural part.